Attachment to geometrical



Nov. 16, 1948. R..H. BUCHHORN 2,454,133

ATTACHMENT TO GEOMETRICAL INSTRUMENT I Filed May 23, 1947 2 Sheets-sheaf1 INVENTOR.

. ELIEhhDT'TL EQM, fig

ATTORNEYS.

Now-16,1948. v R. H, BUCHHORN 2,454,133

ATTACHMENT T0 GEOMETRICAL INSTRUMENT Filed May 23, 1947 2 Sheets-Sheet 250 g a INVENTOR. IIIIIIAfi/III 7737 H EUBhhUTTL ATTORNEY Patented Nov. 16, 1948 ATTACHMENT TO GEOMETRICAL INSTRUMENTS Robert H. Buchhorn, TexasCity, Tex.

Application May 23, 1947, Serial N0. 750,055

4 Claims.

This invention relates to attachments to geo' metrical instruments ofthe straight-edge type and more particularly to a protractor-level-sightattachment to a so-called carpenters framing square.

An important object of the invention is to provide a novelprotractor-level-sight attachment to carpenters framing squares notequipped with protractors, but which attachment may be readily adaptedfor use with such squares having protractors.

Another important object is to provide such an attachment which may besecured to and removed from a square, by making only a minor change inthe latter, which change interferes in no way with the conventional useof the square when the attachment is removed.

Still another important object is to provide a protractor-level-sightattachment, comprising three main parts or portions, detachably securedtogether, with the portions so disposed that they are readily accessiblefor use, as a unit.

Other objects and advantages of the invention will be apparent duringthe course of the following detailed description of the invention, takenin connection with the accompanying drawings, forming a part of thisspecification, and in which drawings:

Figure 1 is a plan view of one face of a carpenters framing square, withthe novel attachments secured to the square.

Figure 2 is a plan view of the opposite face thereof, with the newattachments secured to the square.

Figure 3 is .an enlarged fragment of one face of the corner portion ofthe square of Figure 1 with the novel protractor-level-sight attachmentsecured to the corner portion.

Figure 4 is an enlarged fragment of the other face of the cornerportion, showing the sight portion of the novel attachment of Figure 3.

Figure 5 is a vertical section upon the line 5--5 of Figure 3.

Figure 6 is a plan View of the protractor portion of the novelattachment, removed from the square.

Figure 7 is .an end elevation thereof.

Figure 8 is a plan view of the sighting portion of the novel attachment,removed from the square.

Figure 9 is an end elevation thereof.

Figure 10 is a vertical section upon the line Ill-l0 of Figure 8.

Figure 11 is a top plan of the new attachment for the shorter blade(tongue) of the square.

Figure 11 is a transverse section thereof upon the line l2l 2 of Figure11.

In the drawings, wherein for the purpose of illustration is shown apreferred embodiment of the invention and wherein similar referencecharacters designate corresponding parts throughout the several views,the letter A designates a linear measuring instrument such as acarpenters framing square, B the novel protractor-level-sightattachment, C a tongue or blade extension and D attaching means for theextension C.

The linear measuring instrument A is shown as a carpenters framingsquare of conventional construction, including two blades l0 and l Iwith their longitudinal axes forming a right angle and merging, one intothe other, at a corner portion [2, Where the inner, longitudinal,preferably beveled edges 13 and M respectively of the blades [0 and IIform a corner [5 and the outer, longitudinal, preferably beveled edges[6 and H respectively of the blades form a corner H3. The corner portionl2 has an upper face l9 and lower face 20 and the remainder of the bladeI 0 has an upper face 2! and lower face 22. However, this conventionalsquare is altered by providing a preferably beveled, circular opening 23in the corner portion l2, as shown in Figure 5 and disposed, as isapparent, particularly in Figure 4 to one side (the blade in side) of animaginary straight line extending from corner [5 to corner 18.

The attachment B is provided for the purpose of laying out, whenproperly attached to the square A, points upon the surfaces ofcylindrical objects, such as ships masts, tubular conduits, columns,pipe, :flagpoles and the like. It is particularly useful when thematerial to be worked upon is raised from the ground, such as disposedupon trestles, but it is useful, also, among other uses, in laying outany degree of angularity upon a Wall surface or the like.

Referring mainly to Figures 5, 6 and '7, there is shown the protractorportion 25 of the novel attachment. This is, preferably, a flat plate 26having an arcuate edge 21 at one end of which is a down-turned lug 28,having a face 29 constructed and arranged to extend along a portion ofthe edge H; of the blade l0, and at the other end is adown-turned lug30, having a face 3| constructed and arranged to extend along a portionof the edge I! of the blade ll, thus anchoring the portion 25 againstmovement from side to side as well as pivotal movement. Inwardl'y of thearcuate edge 21 there is suitable indicia, as degree graduations 30' anddegree numerals designated generally as 3|. The plate 26 is providedwith a perforation 32 for the shank of a coupling or fastening means forsecuring the protractor portion to the square A with the shank passingthrough the opening 23 and to be described more fully later in thisspecification, whereby the protractor portion 25 will be disposed uponthe upper face |9 of the corner portion l2. The lugs 28 and 30 are of athickness no greater than the thickness of the blades ID or H and theyare so disposed that, when the protractor portion 25 is slipped intoplace the opening 23 and perforation 32 will axially align.

Referring now mainly to Figures 3 and 5, above the protractor portion 25is the index-and-levelcarrying portion 35 consisting of theindex-carrying section 36 and level-carrying section 31, The section 36may be a disc having a beveled edge 38 containing four index marks orlines 39 disposed 90 apart. The section 36 is provided with a suitableopening or perforation 40 for the shank referred to above; which shankprovides a pivot for the section 36. The radius of the section 36 isless than that of the arcuate edge 21 of the protractor portion so that,when the section 36 is disposed upon the portion 25, the indicia 30' and3| will be exposed as in Figure 3.

Secured to the section 36 inany approved way, as by solder, is thesection 31. This may be a bracket formed of a single length of suitablematerial providing a level-retaining cradle 4|, which may be circular intransverse cross section, as in Figure 5, having a suitable opening 42to expose the spirit level 43 when the latter is retained by the cradle4|. From the cradle extends an attaching tongue or arm 44 having a hole45 for the shank mentioned. Obviously, the longitudinal axis of thelevel 43 will be normal to the prolongation of one of the index marks orlines 39.

Referring now to Figures 8, 9 and 10, there is shown the third portionof the attachment B. This is the sights-carrying portion 50, comprisingan elongated bar or member 5| with a sight 52 preferably at each end andwith the notches 53 of the sights in alignment. These sights which arein the form of lugs project outwardly from the outer face 54 of themember 5|. There are also provided two lugs 55 extending from theopposite face 56 of the member 5|, one having a face 51 constructed andarranged to contact the edge I6 of the blade I0 and the other having aface 58 to contact the edge I! of the blade it, thus preventing rockingof the portion 50'. This portion 50 is disposed upon the face 20 of thecorner portion l2 and is provided with a countersunk opening 59 for theaccommodation of a coupling means 6|] to be next described and forming apart of the attachment B. I

The means 60 may be a bolt GI and nut 62. The bolt 6| preferably has aflat head 63, has a shank 64, screw-threaded adjacent its free endandthe nut 62 may be a wing nut. The head 63 is adapted to fit into theopening 59, the smooth periphery of the shank extends into the openingor perforation 40 of the section 36 and hole 45 of the section 3! and,protruding therefrom, its screw-threaded free end is adapted to carrythe wing nut normally bearing against the outer face of the section 31.

One example of the use of the square A. and attachment B is as follows:1

With all three portions 25, 35 and 50 in place, as in Figures 1 and 2,and the nut 62 retightened.

after the level carrying portion 35 has been rotated until a line 39coincides with the desired degree graduation 36 on the portion 25.Thereupon, the square A is moved circumferentially about a pipe, forexample, with the two blades I0 and H contacting the pipes peripheryalong their edges l3 and I4 until the bubble of the level indicates thelongitudinal axis of the level is horizontal. The operator now sightsalong the notches 53 and thus obtains and suitably fixes the startingpoint upon the pipe. Next, with the desired degree of angularity fixedby a line 39 and degree graduation 3|), the square is moved horizontallyabout the pipe, with the edges i3 and M in contact therewith until thebubble indicates a level position, using the sight notches 53, thesecond point is obtained and fixed upon the pipe. A line drawn from onepoint to the other indicates the angular line desired.

It is desirable to have the blade It (sometimes known as the tongue) aslong as the blade when employing the attachment B. In conventionalcarpenters squares, this is not the case. Therefore, I have provided theblade extension C and its attaching means D, shown more particularly inFigures 11 and 12.

The tongue or blade extension C may be of the same width as the blade ortongue U], have a beveled edge if! to join and continue the edge l3 andan opposite edge 7| to join and continue the edge l6.

The attaching means D for the blade extension C comprises, preferably,an elongated member or strip 75 suitably rigidly secured at one endportion 76 to one face of the blade extension C and provided with asuitable number of spaced-apart crossarms Tl each having a slot 18 toreceive a portion of the blade ||l adjacent its free end. One of thesecrossarms l'l may carry a set screw 79 extending into its slot 78, as inFigure 12 so that the free end of its shank 80 will contact a blade Itinserted into the slot 18 and thus detachably secure the blade H! to theblade extension C.

The extension C and its attaching means D is employed in laying outlarge-diametered pipe, columns and the like since the shorter blade i!)would handicap the operator in such work.

Various changes may be made to the form of the invention shown anddescribed without departing from the spirit of the invention or scope ofthe claims.

What is claimed is:

1. In an attachment for a linear measuring instrument provided with apair of blades fixed to each other and converging together to a cornerportion having opposite faces, with an opening extending from face-toface, said attachment including a first portion disposed upon one ofsaid faces, provided with degree graduations upon its outer face, anopening and means to prevent rotation of said first. portion relative tosaid blades and to position said first portion so that the axes of saidopenings will coincide; a second portion rotatable over the outer faceof said first portion exclusive of the degree graduationscarryingsection thereof, said second portion having an index, a circularopening, a bracket, and a spiritlevel carried by said bracket. with thelongitudinal axis of the index normal to the longi tudinal axis of thelevel; a third portion disposed upon the other of the faces of saidcorner portion, provided with a pair of sights, one in alignment withthe other, an opening and meansto prevent rotation of said thirdportion. relative tosaid blades and to position said third portion sothat the axis of the opening therein will coincide with the axis of thefirst-mentioned opening; and means to detachably secure said first,second and third portions to said corner portion, including a shankextending through all of said openings.

2. In an attachment for a linear measuring instrument provided with apair of blades fixed to each other, having side edges, convergingtogether to a corner portion having opposite faces, with an openingextending from face to face, said attachment including a first portiondisposed upon one of said faces, provided with degree graduations, uponits outer face, an opening and means to prevent rotation of said firstportion relative to said blades and to position said first portion sothat the axes of said openings will coincide, including lugs extendingto and in contact with two of said side edges; 2, second portionrotatable over the outer face of said first portion exclusive of thedegree graduations-carrying section thereof, said second portion havingan index, a circular opening, a bracket, and a spirit level carried bysaid bracket with the longitudinal axes of the index normal to thelongitudinal axis of the level; a third portion disposed upon the otherof the faces of said corner portion, provided with a pair of sights, onein alignment with the other, an opening and means to prevent rotation ofsaid third portion relative to said blades and to position said thirdportion so that the axis of the opening therein will coincide with theaxis of the first-mentioned opening; and means to detachably secure saidfirst, second and third portions to said corner portion, including ashank extending through all of said openings.

3. In an attachment for a linear measuring instrument provided with apair of blades fixed to each other, having side edges, convergingtogether to a corner portion having opposite faces, with an openingextending from face to face, said attachment including a first portiondisposed upon one of said faces, provided with degree graduations uponits outer face, an opening and means to prevent rotation of said firstportion relative to said blades and to position said first portion sothat the axes of said openings willcoincide, including lugs extending toand in contact with two of said side edges; a second portion rotatableover the outer face of said first portion exclusive of thedegree-graduations carrying section thereof, said second portion havingan index, a circular opening, a bracket, and a spirit level carried bysaid bracket with the longitudinal axis of the index normal to thelongitudinal axis of the level; a third portion disposed upon the otherof the faces of said corner portion, provided with a pair of sights, onein alignment with the other, an

tion said third portion so that the axis of the opening therein willcoincide with the axis of the first-mentioned opening; including lugsextending to and in contact with two of said side edges; and means todetachably secure said first, second and third portions to said cornerportion, including a shank extending through all of said openmgs.

4. In an attachment for a carpenters forming square provided with aperforation at its corner portion, said attachment including a firstportion disposed upon one of the faces of said corner portion, saidfirst portion comprising a flat plate having a perforation, an arcuateedge and a downturned lug at each end of said arcuate edge, with saidlugs in contact with edges of said square when the axes of saidperforations coincide, said first portion having .degree graduations atsaid arcuate edge; a second portion having a perforation, aligned withsaid first-named perforation and comprising an index-carrying sectionand a level-carrying section, said index-carrying section being a discprovided with indices disposed at its edge, and apart, said disc havinga periphery spaced inwardly of said arcuate edge, said levelcarryingsection fixed to the index-carrying section and provided with a spiritlevel with its longitudinal axis parallel to the longitudinal axes oftwo of said indices; a third portion mounted upon the other of saidfaces of said corner portion comprising an elongated bar having a pairof spacedapart sights extending normal thereto, a perforationintermediate the sights and a pair of lugs, with said last-named lugsconstructed and arranged to contact the edges of said square when theaxis of said last-named perforation coincides with the axis of saidfirst-named perforation; and means to detachably secure said first,second and third portions to said corner portion and rotatably mountingsaid index-carrying section on said first portion, including a shankextending through all of said perforations.

ROBERT H. BUCHI-IORN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 51,375 Wiley Dec, 5, 1865 129,311Biggs July 16, 1872 224,401 Derickson Feb. 10, 1880 1,365,991 HeldenJan. 18, 1921 1,428,669 Watson Sept. 12, 1922 2,311,323 Addis Feb. 16,1943 FOREIGN PATENTS Number Country Date 83,375 Germany 1895

